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neodymium magnets

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SM 25x275 [2xM8] / N42 - magnetic roller

magnetic separator

catalog number 130294

GTIN: 5906301812876

5.0

diameter Ø

25 mm [±0,1 mm]

height

275 mm [±0,1 mm]

max. temperature

≤ 80 °C

762.60 gross price (including VAT) / pcs +

620.00 ZŁ net price + 23% VAT / pcs

bulk discounts:

need more quantity?

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Specification: magnetic separator 25x275 [2xM8] / N42

Characteristics: magnetic separator 25x275 [2xM8] / N42
Properties
Values
catalog number
130294
production / distribution
Dhit sp. z o.o.
country of origin
Poland / China / Germany
customs code
85059029
diameter Ø
25 mm [±0,1 mm]
height
275 mm [±0,1 mm]
max. temperature ?
≤ 80 °C
weight
0.01 g
execution tolerance
± 0.1 mm
rodzaj materiału
AISI 304 - bezpieczna dla żywności
rodzaj magnesów
NdFeB N42
ilość gwintów
2x [M8] wewnętrzne
biegunowość
obwodowa - 10 nabiegunników
indukcja magnetyczna
~ 6 500 Gauss [±5%]
max. temp. pracy
poniżej ≤ 80°C
grubość rury osłonowej
1 mm

Magnetic properties of the material N42

material characteristics N42
Properties
Values
units
remenance Br [Min. - Max.] ?
12.9-13.2
kGs
remenance Br [Min. - Max.] ?
1290-1320
T
coercivity bHc ?
10.8-12.0
kOe
coercivity bHc ?
860-955
kA/m
actual internal force iHc
≥ 12
kOe
actual internal force iHc
≥ 955
kA/m
energy density [Min. - Max.]
40-42
BH max MGOe
energy density [Min. - Max.]
318-334
BH max KJ/m
max. temperature
≤ 80
°C

Physical properties of sintered neodymium magnets Nd2Fe14B

Physical properties of sintered neodymium magnets Nd2Fe14B
Properties
Values
units
Vickers hardness
≥550
Hv
Density
≥7.4
g/cm3
Curie Temperature TC
312 - 380
°C
Curie Temperature TF
593 - 716
°F
Specific resistance
150
μΩ⋅Cm
Bending strength
250
Mpa
Compressive strength
1000~1100
Mpa
Thermal expansion parallel (∥) to orientation (M)
(3-4) x 106
°C-1
Thermal expansion perpendicular (⊥) to orientation (M)
-(1-3) x 10-6
°C-1
Young's modulus
1.7 x 104
kg/mm²
The magnetic separator, namely the magnetic roller, uses the power of neodymium magnets, which are placed in a casing made of stainless steel mostly AISI304. In this way, it is possible to precisely separate ferromagnetic elements from other materials. A key aspect of its operation is the use of repulsion of magnetic poles N and S, which allows magnetic substances to be collected. The thickness of the magnet and its structure pitch affect the power and range of the separator's operation.
Generally speaking, magnetic separators are used to extract ferromagnetic particles. If the cans are made from ferromagnetic materials, a magnetic separator will be effective. However, if the cans are made of non-ferromagnetic materials, such as aluminum, the magnetic separator will not be effective.
Yes, magnetic rollers are used in the food industry to remove metallic contaminants, such as iron fragments or iron dust. Our rollers are made from acid-resistant steel, AISI 304, suitable for contact with food.
Magnetic rollers, often called cylindrical magnets, are used in metal separation, food production as well as recycling. They help in eliminating iron dust during the process of separating metals from other wastes.
Our magnetic rollers are composed of neodymium magnets placed in a stainless steel tube cylinder of stainless steel with a wall thickness of 1mm.
Both ends of the magnetic bar will be with M8 threaded holes - 18 mm, enabling simple mounting in machines or magnetic filter drawers. A "blind" version is also possible in manual separators.
In terms of features, magnetic bars stand out in terms of magnetic force lines, flux density and the field of the magnetic field. We produce them in two materials, N42 and N52.
Generally it is believed that the greater the magnet's power, the more efficient it is. But, the effectiveness of the magnet's power is based on the height of the used magnet and the quality of the material [N42] or [N52], as well as on the area of application and expected needs. The standard operating temperature of a magnetic bar is 80°C.
When the magnet is thin, the magnetic force lines will be short. On the other hand, when the magnet is thick, the force lines are extended and extend over a greater distance.
For constructing the casings of magnetic separators - rollers, frequently stainless steel is utilized, particularly types AISI 316, AISI 316L, and AISI 304.
In a saltwater contact, AISI 316 steel exhibits the best resistance thanks to its outstanding corrosion resistance.
Magnetic rollers stand out for their specific arrangement of poles and their capability to attract magnetic substances directly onto their surface, as opposed to other separators that often use complex filtration systems.
Technical designations and terms related to magnetic separators include among others polarity, magnetic induction, magnet pitch, as well as the type of steel used.
Magnetic induction for a roller is determined using a teslameter or a gaussmeter with a flat Hall-effect probe, seeking the highest magnetic field value close to the magnetic pole. The outcome is checked in a value table - the lowest is N30. All designations below N27 or N25 suggest recycling that falls below the standard - they are not suitable.
Neodymium magnetic rollers offer many advantages, including higher attracting power, longer lifespan, and effectiveness in separating fine metal particles. Disadvantages may include the requirement for frequent cleaning, greater weight, and potential installation difficulties.
For proper maintenance of neodymium magnetic rollers, it is recommended regularly cleaning them from contaminants, avoiding high temperatures up to 80°C, and protecting them from moisture if the threads are not sealed – in ours, they are. The rollers our rollers have waterproofing IP67, so if they are not sealed, the magnets inside can rust and weaken. Testing of the rollers should be carried out once every 24 months. Care should be taken, as there is a risk getting pinched. If the protective tube is only 0.5 mm thick, it may wear out, which in turn could lead to problems with the magnetic rod seal and product contamination. The effective range of the roller is equal to its diameter: fi25mm gives an active range of about 25mm, while fi32 gives an active range of about 40mm.
Magnetic rollers are cylindrical neodymium magnets placed in a casing made of corrosion-resistant stainless steel, which are used to remove metal contaminants from bulk and granular materials. They are applied in industries such as food processing, ceramics, and recycling, where the removal of iron metals and iron filings is essential.

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Advantages and disadvantages of neodymium magnets NdFeB.

Apart from immense strength, neodymium magnets have the following advantages:

  • They do not lose their power (of the magnet). After approximately 10 years, their power decreases by only ~1% (theoretically),
  • They are highly resistant to demagnetization by external magnetic sources,
  • By applying a shiny coating of nickel, gold, or silver, the element gains an aesthetic appearance,
  • They possess very high magnetic induction on the surface of the magnet,
  • Magnetic neodymium magnets are characterized by hugely high magnetic induction on the surface of the magnet and can operate (depending on the form) even at temperatures of 230°C or higher...
  • Thanks to the flexibility in shaping or the ability to adapt to specific requirements – neodymium magnets can be produced in various forms and dimensions, which amplifies their universality in usage.
  • Key role in the industry of new technologies – are used in hard drives, electric drive mechanisms, medical equipment or very modern machines.

Disadvantages of neodymium magnets:

  • They are prone to breaking as they are fragile when subjected to a powerful impact. If the magnets are exposed to impacts, it is suggested using magnets in a metal holder. The steel housing in the form of a holder protects the magnet from impacts and also increases its overall strength,
  • Magnets lose their strength due to exposure to high temperatures. In most cases, when the temperature exceeds 80°C, these magnets experience permanent loss in strength (although it is worth noting that this is dependent on the form and size of the magnet). To avoid this problem, we offer special magnets marked with the [AH] symbol, which exhibit high temperature resistance. They can operate even at temperatures as high as 230°C or more,
  • Magnets exposed to a humid environment can corrode. Therefore, when using them outdoors, we suggest using waterproof magnets made of rubber, plastic, or other moisture-resistant materials,
  • The use of a cover or a magnetic holder is recommended due to the limited possibilities of manufacturing threads or complex shapes in the magnet
  • Potential hazard to health from tiny fragments of magnets pose a threat, in case of ingestion, which is particularly important in the aspect of protecting young children. Additionally, tiny parts of these magnets can complicate diagnosis in case of swallowing.

Exercise Caution with Neodymium Magnets

Avoid bringing neodymium magnets close to a phone or GPS.

Magnetic fields interfere with compasses and magnetometers used in navigation for air and sea transport, as well as internal compasses of smartphones and GPS devices.

Neodymium magnets should not be near people with pacemakers.

Neodymium magnets generate strong magnetic fields. As a result, they interfere with the operation of a pacemaker. This happens because such devices have a function to deactivate them in a magnetic field.

  Magnets are not toys, children should not play with them.

Not all neodymium magnets are toys, so do not let children play with them. Small magnets pose a serious choking hazard or can attract to each other in the intestines. In such cases, the only solution is to undergo surgery to remove the magnets, and otherwise, it can even lead to death.

Comparing neodymium magnets to ferrite magnets (found in speakers), they are 10 times more powerful, and their strength can surprise you.

Make sure to review all the information we have provided. This will help you avoid harm to your body and damage to the magnets.

Magnets made of neodymium are noted for being fragile, which can cause them to crumble.

In the event of a collision between two neodymium magnets, it can result in them getting chipped. Despite being made of metal as well as coated with a shiny nickel plating, they are not as hard as steel. In the case of a collision between two magnets, there can be a scattering of small sharp metal fragments in different directions. Protecting your eyes is essential.

Dust and powder from neodymium magnets are flammable.

Avoid drilling or mechanical processing of neodymium magnets. Once crushed into fine powder or dust, this material becomes highly flammable.

The magnet coating contains nickel, so be cautious if you have a nickel allergy.

Studies clearly indicate a small percentage of people who suffer from metal allergies such as nickel. An allergic reaction often manifests as skin redness and rash. If you have a nickel allergy, you can try wearing gloves or simply avoid direct contact with nickel-plated neodymium magnets.

Neodymium magnets can become demagnetized at high temperatures.

Although magnets have shown to retain their effectiveness up to 80°C or 175°F, this temperature may vary depending on the type of material, shape, and intended use of the magnet.

Neodymium magnets are primarily characterized by their significant internal force. They attract to each other, and any object that comes in their way will be affected.

If the joining of neodymium magnets is not under control, then they may crumble and crack. You can't approach them to each other. At a distance less than 10 cm you should have them very firmly.

Make sure not to bring neodymium magnets close to the TV, wallet, and computer HDD.

Neodymium magnets generate intense magnetic fields that can destroy magnetic media such as floppy disks, video tapes, HDDs, credit cards, magnetic ID cards, cassette tapes, or other devices. They can also damage videos, televisions, CRT computer monitors. Do not forget to keep neodymium magnets at a safe distance from these electronic devices.

In order for you to know how powerful neodymium magnets are and why they are so dangerous, see the article - Dangerous very powerful neodymium magnets.

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e-mail: bok@dhit.pl

tel: +48 888 99 98 98